Portion of a toothbrush



FIG. 1 is a left, frontal perspective view of a portion of a toothbrushshowing my new design;

FIG. 2 is a right, rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof, the left side view being a mirrorimage thereto;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a top view thereof.

The broken line showing of a bristled head illustrates environmentalstructure that forms no part of the claimed design.

The ornamental design for a portion of a toothbrush, as shown and described. 